Signatures

Verify an ECDSA signature

POSThttps://ecdsa.com/api/v1/verify

Verifies a signature over a message (or a precomputed digest) against a public key. Curves: P-256, P-384, P-521, secp256k1. Signature formats auto-detected: ASN.1 DER or raw r‖s, in hex, base64 or base64url. Public key formats: PEM SPKI ("PUBLIC KEY"), EC JWK, or a bare SEC1 point in hex/base64. A signature that simply does not verify returns valid: false with HTTP 200; only unparseable input yields 400.

API-Schlüssel: Optional; ein Schlüssel braucht den Scope api
Kontingentverbrauch mit Schlüssel: 1 Einheit pro Aufruf
Rate Limit: 60 Anfragen/min pro IP

Anfrage

JSON-Body: VerifyRequest

Feld	Typ	Erforderlich	Beschreibung
publicKey	string	ja	PEM "PUBLIC KEY" (SPKI), EC JWK JSON, or a bare SEC1 point in hex/base64.
message	string	ja	The signed message (or its digest — see messageIsDigest).
signature	string	ja	DER or raw r‖s signature in hex, base64 or base64url (auto-detected).
hash	string	nein	Digest applied to the message (ignored when messageIsDigest is true). Standardwert "SHA-256" einer der Werte "SHA-256", "SHA-384" oder "SHA-512"
curve	string	nein	Force a curve, or auto to infer it from the key. Standardwert "auto" einer der Werte "auto", "P-256", "P-384", "P-521" oder "secp256k1"
messageEncoding	string	nein	How the message string encodes bytes. Standardwert "utf8" einer der Werte "utf8", "hex" oder "base64"
messageIsDigest	boolean	nein	When true, message bytes are used as the digest directly (no hashing). Standardwert false

Antworten

200Verification outcome.

Feld	Typ	Erforderlich	Beschreibung
valid	boolean	ja
curve	string \| null	ja	Curve the signature verified on (or the single candidate when it did not).
curvesTried	string[]	ja	Every curve tried, in order.
keySource	string	ja	How the public key was encoded. einer der Werte "pem-spki", "jwk" oder "raw-point"
signatureFormat	string	ja	einer der Werte "der" oder "raw"
details	object	ja
details.r	string	ja	r as hex.
details.s	string	ja	s as hex.
details.highS	boolean	ja	s > n/2 (non-canonical for Bitcoin & co).
notes	string[]	ja	Per-curve diagnostics.

Header: X-Request-Id · X-RateLimit-Limit · X-RateLimit-Remaining · X-RateLimit-Reset · X-Quota-Limit · X-Quota-Remaining · X-Quota-Reset

Status	Bedeutung	Codes
400	Bad request. Input limits: a request body of at most 100 KB (a larger one is answered with 413) and arrays and objects nested at most 64 levels deep, JSON documents inside string fields included.	invalid_json missing_field invalid_input private_key_rejected
401	Unauthorized.	unauthorized
403	Forbidden.	forbidden_scope
404	Not found.	not_found
405	Method not allowed.	method_not_allowed
413	Payload too large.	payload_too_large
429	Too many requests.	rate_limited quota_exceeded
500	Internal server error.	internal_error
503	Service unavailable.	service_unavailable
504	Gateway timeout.	timeout

Jede Fehlerantwort enthält das JSON-Fehlerobjekt; die Fehlertabelle erklärt, was jeder Code bedeutet und was zu tun ist.

Beispiel

P-256 key as PEM, UTF-8 message, DER signature

curl

curl -sS 'https://ecdsa.com/api/v1/verify' \
  -H 'content-type: application/json' \
  -d '{
  "publicKey": "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE4+8TCP3Hop/Acb8L7reksO9flyt1\nsUhvEqUs7a45RVDRDtAIZdTnOJcAhTCQvdzUBO4KUyxSRcZm6ro+2RGfSQ==\n-----END PUBLIC KEY-----",
  "message": "The quick brown fox jumps over the lazy dog",
  "signature": "3045022100df542bb71e0e3019086f1b1ba51f1aa0ec5e6afca05c3f5a7f4f02f5b7c39d24022030c59f1ac6d8c6893fb2a5ac8dfd9388d31ebd3382510dcfb7f28f9182eb1131"
}'

JavaScript (fetch)

const response = await fetch("https://ecdsa.com/api/v1/verify", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "publicKey": "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE4+8TCP3Hop/Acb8L7reksO9flyt1\nsUhvEqUs7a45RVDRDtAIZdTnOJcAhTCQvdzUBO4KUyxSRcZm6ro+2RGfSQ==\n-----END PUBLIC KEY-----",
    "message": "The quick brown fox jumps over the lazy dog",
    "signature": "3045022100df542bb71e0e3019086f1b1ba51f1aa0ec5e6afca05c3f5a7f4f02f5b7c39d24022030c59f1ac6d8c6893fb2a5ac8dfd9388d31ebd3382510dcfb7f28f9182eb1131"
  }),
});
console.log(response.status, await response.json());

Python (httpx)

import httpx

response = httpx.post(
    "https://ecdsa.com/api/v1/verify",
    json={
        "publicKey": "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE4+8TCP3Hop/Acb8L7reksO9flyt1\nsUhvEqUs7a45RVDRDtAIZdTnOJcAhTCQvdzUBO4KUyxSRcZm6ro+2RGfSQ==\n-----END PUBLIC KEY-----",
        "message": "The quick brown fox jumps over the lazy dog",
        "signature": "3045022100df542bb71e0e3019086f1b1ba51f1aa0ec5e6afca05c3f5a7f4f02f5b7c39d24022030c59f1ac6d8c6893fb2a5ac8dfd9388d31ebd3382510dcfb7f28f9182eb1131",
    },
    timeout=30.0,
)
print(response.status_code, response.json())

Antwort 200

{
  "valid": true,
  "curve": "P-256",
  "curvesTried": [
    "P-256"
  ],
  "keySource": "pem-spki",
  "signatureFormat": "der",
  "details": {
    "r": "df542bb71e0e3019086f1b1ba51f1aa0ec5e6afca05c3f5a7f4f02f5b7c39d24",
    "s": "30c59f1ac6d8c6893fb2a5ac8dfd9388d31ebd3382510dcfb7f28f9182eb1131",
    "highS": false
  },
  "notes": []
}

Die Antwort der API auf dieses Beispiel, erzeugt für diese Seite am 20. Oktober 2026; relative Zeitangaben und Tageszahlen darin beziehen sich auf diesen Tag.

Fehlercodes

Code	Status	Bedeutung
invalid_json	400	The body is not valid JSON or not a JSON object; or the input nests arrays and objects more than 64 levels deep (JSON documents inside string fields count too), or is too complex to inspect for private keys.
missing_field	400	A required field is absent or empty.
invalid_input	400	A field could not be parsed — the message explains exactly why.
private_key_rejected	400	The request contains private-key material (a PEM PRIVATE KEY block, an OpenSSH, SSH2 or PuTTY private key, or a JWK with "d"). Never send private keys anywhere.
unauthorized	401	The Authorization or X-API-Key header is malformed, the API key is not valid (wrong checksum, unknown, revoked or expired), or the operation needs a key.
forbidden_scope	403	The API key is valid but lacks a scope this operation requires; the message names it.
not_found	404	No operation exists at this path.
method_not_allowed	405	The path exists but does not accept this HTTP method; see the Allow header.
payload_too_large	413	The body exceeds 100 KB.
rate_limited	429	Too many requests — see Retry-After.
quota_exceeded	429	A daily or monthly quota of the API key's account is used up. X-Quota-Reset (and Retry-After) say when it starts over; retrying earlier cannot succeed.
internal_error	500	Unexpected server error.
service_unavailable	503	API keys cannot be verified right now (the key store is unreachable); retry shortly.
timeout	504	The operation did not finish within its time budget.

Schemas

Error

The error envelope of every non-2xx response.

Feld	Typ	Erforderlich	Beschreibung
error	object	ja
error.code	string	ja	Machine-readable error code. Each response lists the codes it can carry; new codes may be added within v1, so treat an unknown code by its HTTP status.
error.message	string	ja	Human-readable explanation (English).
error.requestId	string	nein	The X-Request-Id of this request — quote it when reporting a problem. Sent since v1.1.
error.detail	object	nein	Structured context for the error, such as the offending field; omitted when there is none. beliebige Feldnamen
error.docs	string	nein	Where the error codes are explained. Sent since v1.1. Format uri

Alle Operationen findest du in der API-Referenz.